Rubber adherent metal



Sept'. 29, 1942. E, Q DOMM 2,296,838

RUBER ADHERENT METAL Filed Nov. 1, 1957 FERROUS HOT Mcm. y VULCANIZED BASE GALVANIZED 0R RUBBER ZINC COBALT H07 /V/Offz GALVAN/Z50 0,9

z//Vc 605,90"

Patented Sept. 29, 1942 RUBBER ADHERENT METAL Elgin Carleton Domm, Niles, Mich., assixnor to National-Standard Company, a corporation of Michigan Application November 1, 1937, Serial No. 172,305

7 Claims.

This invention relates to rubber adherent metal, and more particularly to a method of coatn ing ferrous and other metals to make them adherent to rubber. As set forth in my Patent 2,002,261, rubber has been attached to steel by the use of brass coatings produced by dipping or Percent Carbon .65 Manganese .80 Phosphorus .015 Sulfur .025 Silicon .095

Balance is iron with traces of impurities.

The wires may be fed continuously from swiits, or the like, through the entire system. They are first cleansed by scraping and then wiping with rags soaked in a grease solvent, such as gasoline. They are then further cleansed by passing througha bath of hydrochloric acid, preferably containing about HCl. The excess acid is removed by wet rags, and the wires then passed through a water bath. They are again passed through acid, this time about 8% HC1 and are again wiped and washed. The number and extent of these cleansing treatments depends, of course, upon the original condition of the wire.

The wire, when thoroughly clean, is then hot galvanized in any suitable manner; for example as disclosed in my Patent 2,002,261. In this process the clean wires are drawn through a ilux, such as a saturated solution of zinc ammonium chloride, the excess solution is removed by a regular wipe and the wires are then drawn through a bath of molten zinc. The temperature of the bath should be between 820 and 840 F. for steel wire bead reinforcing wires of .the composition hereinbeiore described. The zinc is deposited to a thickness of approximately j/4000 to 1151000 of an inch. For example, with a wire of .043 inch diameter, weighing 4.88 lbs. per 1000 .feet of wire, the weight of the zinc is about 8 to 20 grams per kilogram of wire. With .037 inch diameter wire, weighing 3.6i lbs. per 1000 feet, the weight of the zinc is about 10 to 24 grams per kilogram.

The zinc alloys itself with the iron to some extent so that about 10 to 25% of the metallic coating is iron. This results in a better bonding than when the zinc is applied electrolytically, but where this bonding action is not required, electrolytic zinc may be used.

After leaving the zinc bath, the excess zinc is removed by an asbestos wiper. The wire may then be cleaned, if desired, and passed to a plating bath.

The nickel or cobalt is applied from any suitable bath oi .these materials.

The amount ci nickel applied'should be at least 0.3 gram of nickel per kilogram of wire of tire bead size, and not over 4 grams per kilogram. Preferably a range of .5 to 2.0 grams is employed.

When cobalt is employed, the amount of material should be substantially the same. The preferred amounts correspond to a thickness of appIOXmRBlY yoom) t0 37210000 Of an inch. The broader range corresponds about to 1/,0000 to 1/400000 oi an inch.

For example, using bead stock A, the following results were obtained:

Lbs. pull/in. Pegfsrfd* Hot Zn-l-. g. Ni 83. 5 82 Het Zn+l.0 g. Ni.. 8l. 0 80 Hot Zn+1.5 g. Ni 83. 4 79 Hot Zink-2.0 g. Ni 83. 3 92 Using cobalt in place of nickel with one particular bead stock showed the following results:

Lbs. pull/in. Peesid Hot Zn+.5 g. Co 73. 4 60 Hot Zn-I-LO g. C-- 73. 6 ig Hot Zn+1.5 g. Co-. 65. 6 37 Hot Zn+2.0 g. Co 66. 3

and another bead stock using cobalt instead of nickel showed the following:

Lbs. pun/in. Pfflfeeslilnad' Hot Zn-l-. g. C0 63. 8 66 Hot Zn+l..0 g. Co (3g Hot Zn+l.5 g. C0 7 s Hot Zn+2.0 g. Co 61.2

Salt spray results were considerably better on the whole with cobalt than with nickel.

Tin, cadmium or lead may be substituted/for the zinc, particularly with the cobalt, `butl the results are far less satisfactory, although cadmium and cobalt gave particularly good results with the second bead stock.

.An example of the tin and cobalt coating with the second bead stock is as follows:

c2. a as so. s 92 Hot Sn+2.0 g. Co 84. 6 87 The following shows results Of cadmium and cobalt on the second bead stock:

The use of electro-zinc instead of hot zinc gave considerably better results, so far as salt spray results were concerned, but the adhesion was less uniform.

The following first bead stock table shows the results with the with cobalt and nickel:

Lbs. pun/iu. Pegcsfinad so. o 97 76. 9 93 7s. 5 s4 s1. 1 g4 dercoating. The rst two columns are the rst bead stock and the second two columns are the second bead stock:

First bead stock Second bead stock Percent Percent Lbs. pull/1n. adhesion Lbs. pull/1n. adhesion .5 g. Ni.. 44. 4 6 66. 0 90 1.0 g. Ni-.. 66. 3 A 40 67. 7 18 1.5 g. Ni--. 66.3 62 66.6 23 2.0 g. Ni... 64. 0 57 48. 6 5

will be employed or where it is possible that the formula may be varied from time to time.

The foregoing detailed description has been given for clearness only, and no unnecessary limitations should be understood therefrom.

I claim:

1. An article designed for adherent vulcanization of rubber thereto comprising a metallic base, a metal of the class consisting of zinc, cadmium, lead and tin thereon, and a coating of metal of the class consisting of nickel and cobalt of a thickness of approximately 1/30000 to 1/400000 of an inch over the intermediate coating.

2. A tire bead wire having a hot galvanized zinc coating thereon and a coating of metal of the class consisting of nickel and cobalt of a thickness of approximately 1.6mm to immun of an inch on the zinc.

3. A tire bead comprising a ferrous base tire bead wire, a hot galvanized zinc coating on the Wire, a coating of a metal of the class consisting of nickel and cobalt of a thickness of approximately Mmmm to l/wmm of an inch on said zinc coating, said coated wire being vulcanized in a mass of tire bead rubber. Y

4. The' method of preparing a rubber coated object which comprises hot galvanizing a ferrous base, electro-depositing a thin layer of metal of the class consisting of nickel and cobalt upon the galvanized surface and vulcanizing a rubber coating thereon.

5. A rubber coated article comprising a ferrous base, a metal of the class consisting of zinc, cadmium, lead and tin thereonl and a coating of a metal of the class consisting of nickel and cobalt having a thickness of approximately Bamm. to 1/lonooo of an inch over the intermediate coating.

6. A rubber coated article comprising a ferrous base, a zinc coating thereon, and a coating of a metal of the class consisting of nickel` and cobalt having a thickness of approximately l/{mnnn to 1/400000 of an inch over the intermediate coating.

7. The method of preparing a rubber coated object which comprises cleaning a high tensile strength steel wire in dilute hydrochloric acid, removing the acid, applying a hot galvanized coating thereto, electro-depositing a thin layer of nickel thereon, and vulcanizing a rubber coating upon the nickel.

ELGIN CARLETON DOMM. 

